1. Field of the Invention
The present invention relates to a lifting device employed in a sliding roof device for a vehicle, in which lifting of the slide roof member is permitted only when the slide roof member reaches its forwardmost position wherein the roof opening is closed.
2. Description of Relevant Art
There is known a sliding roof device in which an opening formed in the roof of a vehicle is selectively opened and closed with a slide roof member which is moved forwardly and rearwardly with the aid of a guide rail assembly.
In such a sliding roof device, the slide roof member is moved downwardly and stored below the vehicle roof behind the opening when the opening is uncovered or open. When the opening is covered or closed, the slide roof member is moved upwardly so that the periphery of the slide roof member is brought into close contact with the periphery of the opening, so as to seal the opening in an air-tight manner. For this purpose, the sliding roof device is provided with means for moving the slide roof member up and down to open and close the opening in the vehicle roof.
A conventional sliding roof device is so designed that a spring means is interposed between the stay of the slide roof member and a member sliding along the guide rail to pull the slide roof member downwardly. The slide roof member is moved upwardly against the elastic force of the spring means at the position wherein the opening is closed.
In the conventional sliding roof device, the slide roof member is pulled by the spring means as described above, and therefore the elastic force of the spring means acts on the various components thereof, resulting in increased frictional resistance which interrupts smooth operation. Further, it is difficult to simplify the construction due to the provision of the spring mechanism.
The most serious problem attendant the conventional sliding roof device resides in the fact that while the slide roof member is being moved forwardly to close the opening, the slide roof member may be abruptly stopped, or an abnormal condition may occur to cause the slide roof member to move upwardly at a position other than the predetermined position.
As a result of extensive research regarding the aforesaid problem associated with a conventional lifting device for the slide roof member in a sliding roof device, the present invention has been arrived at to effectively solve the shortcomings and problems associated with such conventional lifting device.